Field of the Invention
This invention relates to a nut to be used as part of a fastener that can be used in multiple different applications and uses for fasteners. One example of the use is the manufacture of wood Crane Mats used in the construction industry to stabilize a working surface for heavy equipment moving over rather soft or environmentally sensitive ground. This invention relates to the use of steel bolts which hold the crane mats together and how they are assembled. It can be utilized with any size bolt.
Description of Related Art
The only known prior art to the nut, is a sleeve nut that is used in the furniture industry. That nut is typically designed for limited torque applications as to not damage the furniture and it is designed so that the bolt cannot pass through the head of the nut and a two bolts cannot engage both the sleeve and the head of the nut at the same time. This limits usage. Because of the purpose of the sleeve nut one does not want the bolt pass through and wants to have coverage for the aesthetic appearance of the furniture.
Typically, prior art crane mats have been held together with 1″ diameter bolts with a formed round head at one end and a length of thread at the other end with a nut and washer. It has been advantageous to countersink the hole on the nut-washer end for two reasons:
1. To recess the nut and washer end so that they do not stick out from the side of the mat—so that mats can be kept tighter together.
2. So that if a bolt is short of coming all the way through—the countersink can allow the nut-washer to reach it inside the recess.
A manufacturer of Crane Mats typically accepts an order for a quantity of mats from its customer, based upon a specified size: Width, Length and Depth (thickness), within specified tolerances. Most critical to the manufacturing process is the overall width of the mat. For instance, a typical width is 4′ in overall width, with a depth of 8″ (cross sectional view of finished Crane Mat). The 4′ width of a wood mat cannot be dimensionally held to exactly 4′, because the saw mill can only “hold” one dimension, in this case the depth, 8″. In the other cut dimension of the log, the sizes become infinite due to the variations in the diameter of the logs and all parties not wishing to waste that part of the log (cost considerations).